1. Field of the Invention
The present invention relates to a method of stopping a desired frame selected among a plural number of frames of a film containing images recorded thereon at a predetermined position.
2. Description of the Prior Art
In a microfilm, a number of images are recorded on the frames of the film respectively. To retrieve an image or images desired in the microfilm there has been, conventionally, used frame marks. The frame marks have been provided on the side edge part of the film one mark for one frame. In feeding the microfilm the frame marks are counted serially and the content of the counter is continuously compared with the frame number of the frame to be retrieved. When the coincidence of count and frame number takes place, the microfilm is stopped at once.
However, there are other kinds of microfilm having no frame marks. In this case, the retrieving method described above can not be used. For such a film having no frame marks, the retrieving of a desired image has been, conventionally, attained by detecting the blank portion (non-image portion) between frames by a sensor. However, this method also has a problem. The interval between adjacent blank portions is not always regular but varies from film to film. Therefore, the film may be stopped in different positions according to the direction film feed. It may be stopped not in the desired position but a deviated position from the desired position. Such deviation of film stop position causes a problem in particular for a reader or a reader-printer by which the recorded image in the microfilm is projected on a screen or on a photosensitive medium with a selected magnification. If there is any deviation of the stop position, the desired image can not correctly be projected on the screen or the image can not completely and correctly be printed on the copy paper. To position the image of the desired frame at the right position, the operator has to additionally adjust the stop position, which may cause a problem for the operator.